1. Field of the Invention
The present invention relates to a heat-sealing apparatus, and more particularly to a heat-sealing apparatus used for heat-fusing a portion to be sealed of a heat-fusible wrapper of e.g. vinyl chloride film, polyethylene film or the like.
2. Description of the Related Art
A conventional heat-sealing apparatus of the above-noted type includes a pair of binding members for vertically binding the portion of the heat-fusible wrapper therebetween. Of these binding members, to a binding face of the lower binding member which is fixed to a casing, there is mounted a heater for heat-fusing the portion of the wrapper to be sealed. On the other than, to a corresponding binding face of the upper binding member, there is affixed a heat-resistant elastic plate-like pressing member along the length of the heater. The apparatus further includes a switching mechanism for switching over the upper binding member between a binding position and a releasing position substantially vertically away from the binding face of the lower binding member (see Japanese laid-open patent gazette Hei. 3-133721, for example).
According to the above-described conventional heat-sealing apparatus, for a heat-sealing operation, the upper binding member is moved substantially vertically toward the binding face of the lower binding member to eventually come into contact with the same, such that an unpleasant binding noise is generated.
Moreover, since the invariably same portion of the elastic pressing member is subjected to the repeated contact with the heater provided in the binding face of the lower binding member, local concentration of damage at this particular portion of the elastic pressing member tends to occur soon.
The present invention addresses to the above problems. A primary object of the present invention is to provide an improved heat-sealing apparatus which can restrict generation of unpleasant binding noise and improve the durability of the elastic pressing roller while heat-fusing a portion of the wrapper in a reliable manner.